Aliens grab too. And where Predators jab wristblades into eye sockets, aliens spear chests on barbed tails and plunge their inner-mouths through foreheads to regain health. You'll gag on your own nostalgia gland as, when playing as the Alien, you realise you can still slash limbs off corpses and leave them lying about the place for their friends to find. Scooting up and down walls is at first disorientating, but soon becomes second nature - and as long as you're in the dark you can take a moment to relax and figure out if you're upside-down or not, just like a real alien probably does.
Darkness effectively makes you invisible to marines who aren't alerted to your presence, working very much like the Predator's cloaking device. Once they know you're nearby however, they'll poke about with flashlights until they've found your hiding place, requiring you to move and jump between shadows, hissing to lure individuals before tearing their faces off in showers of blood, skin and bone.
So those are the campaigns. Three discrete experiences, each one adapted to suit the mechanics of its given species, with the Marine's more fully realised than the others. Number Six's journey ends all too abruptly, and does away with the fun larval stages in AvP2. It literally (and this isn't a spoiler) winces and dies (maybe) of sadness, three hours before you'd expect.
The Predator's amazing and explosive murder-jaunt, on the other hand, doesn't offer the level of tension you experience as a huddled, terrified Marine. What it offers instead is glorious disgust. Hitting those fear-notes by draping silhouettes of scary objects in front of you is something Rebellion excel at, and the Predator campaign, while a panacea for the feeling of vulnerability you're left with having finished the Marine section, certainly isn't where AvP's best bits lie.
They lie instead in the game's multiplayer, a collection of game modes lifted from the popular sports of the day: straight deathmatch; a Left 4 Dead-style Survival mode in which you and three other marines defend yourselves against waves of xenomorphs; a Domination game mode in which aliens and marines fight to control three points of the map; Infection, in which a team of marines is whittled down by aliens, with each fallen human joining the ranks of the increasingly powerful alien brood; and Predator Hunt, which pitches one player as the Predator, slaughtering other players before passing the mantle on to the one who bests him in battle.
Crucially, they all work within the context of the three characters and their abilities. Survival is the co-op mode you dreamt of after watching Aliens - a desperate last stand against an unending tide of flashing claws and teeth. It's a basic, boiled down affair though, featuring nought but players, their guns (with an occasional auto-aiming, xeno-seeking smartgun drop), and an endless supply of angry, angry scuttling enemies.
Elsewhere, the straightforward three-way deathmatch appears finely balanced. Both aliens and Predators can perform their unblockable trophy kills by moving behind enemies and hammering the E key. Once locked into the gruesome animation, the attacker is then at his most vulnerable, creating the potential for a ridiculous conga line of trophy killers, or for one intelligent player to hold back and toss a few grenades or plasma cannon rounds into the fray. Marines lack the ability to tear bones right out of another player's body, and instead rely on countering melee attacks, which gives them more than enough time to pile a few shotgun rounds into their stumbled victim.